1. Field of the Invention
This invention disclosure relates to thermal suppression and more particularly to a means and technique for reducing the thermal signature of equipment, such as engines and generators, to a level whereby the temperature of the equipment would be essentially indiscernable from the background temperature.
2. Description of the Prior Art
It is well known that modern thermal systems can detect and recognize, at very long ranges, targets having a temperature differential as small as 6.degree. C. above the background temperature. Such a detection capability clearly amplifies the necessity for developing more efficient means and techniques for suppressing detectable thermal radiation.
Engine-generator (EG) sets, for instance, have outstanding thermal signatures due to their hot surfaces and hot engine parts which, in some instances, exceed 300.degree. C. All EG sets are very hot by definition and are easily detectable. Such a high thermal visibility for EG sets presents a very serious military problem and will become increasingly more serious as thermal detectors become more common for field use. Obscuring, from detection and recognition, equipment having a temperature greater than that of the background temperature is referred to as thermal suppression. Numerous attempts have heretofore been made to thermally suppress EG sets, but in each suppressor design serious deficiencies have been encountered.
Efforts have been made to direct the hot gases away from the source and/or to cover the source with a thermal blanket, but these techniques were found to be ineffective when viewed from low flying platforms or from ground level and, in fact, introduced other serious problems in the form of solar heating and night cooling.